当我按下通知栏中的通知时，我试图打开一个片段。我的应用程序结构是：

• 具有导航抽屉式菜单的基本Activity
• 和一些从菜单中打开的片段

当我按下通知时，Activity重新打开，但不在指示的片段中，并且在LogCat中，来自指示片段的数据看起来打开并加载，但不使用UI。
通知代码：

NotificationCompat.Builder  mBuilder = 
    new NotificationCompat.Builder(this);   
      mBuilder.setContentTitle("Comanda Noua");
      mBuilder.setContentText("S-a introdus o comanda noua");
      mBuilder.setTicker("Comanda noua!");
      mBuilder.setSmallIcon(R.drawable.calculator_icon);
     mBuilder.setAutoCancel(true);//inchide notificare dupa ce s-a dat click pe ea

      //creste numar notificare
      mBuilder.setNumber(++numMessages);

      // cream un intent 
      Intent resultIntent = new Intent(this, MainActivity.class);

      //am setat actiune pentru a deschide fragmentul corespunzator notificartii la apasare
      resultIntent.setAction("Action1");
      TaskStackBuilder stackBuilder = TaskStackBuilder.create(this);
      stackBuilder.addParentStack(MainActivity.class);

      // Adds the Intent that starts the Activity to the top of the stack 
     stackBuilder.addNextIntent(resultIntent);
      PendingIntent resultPendingIntent =
         stackBuilder.getPendingIntent(0, PendingIntent.FLAG_UPDATE_CURRENT);

      mBuilder.setContentIntent(resultPendingIntent);

      mNotificationManager =(NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

      // notificationID allows you to update the notification later on. 
      mNotificationManager.notify(notificationID, mBuilder.build());

按下通知时打开片段的代码：

Intent intent = getIntent();
   try{
        String action = intent.getAction();
       // Log.d("action:",action);

        if(action.equals("Action1")){
             //Log.d("deschidem agenda:",action);
            AgendaFragment fragment = new AgendaFragment();
         FragmentTransaction transaction = getFragmentManager()
                    .beginTransaction();
         transaction.replace(R.id.frame_container, fragment)
            .setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN)
            .addToBackStack(null).commit();
        }else{
           Log.d("eroare", "Intent was null");
        }
   }catch(Exception e){
        Log.e("eroare", "Problem consuming action from intent", e);             
    }

为什么活动打开而片段没有？